Signal transduction in neutrophil chemotaxis

This review discusses current knowledge on signal transduction pathways con trolling chemotaxis of neutrophils and similar cells. Most neutrophil chemo attractants bind to seven-transmembrane-Helix receptors. These receptors ac tivate trimeric G proteins of the Gi class in neutrophils to initiate chemo taxis. Phospholipases CP, phosphoinositide 3-kinase gamma, and PH domain-co ntaining proteins play various roles in signaling further downstream. The a ctin cytoskeleton is crucial for cell motility, and is controlled by Rho fa mily GTP-binding proteins. PIP 5-kinase, LIM kinase, myosin light chain kin ase and phosphatase, or WASP-like proteins may be important links between R ho GTPases and actin during chemotaxis. Newly emerging ideas on the regulat ion of the "compass" of chemotaxing cells, which may involve Cdc42 and cert ain PH domain-containing proteins, are also presented.